Hirugami Onsen Nitchoan Keigetsu

A 20-room inn in the 'starry village' of Achi with huge kōyamaki-wood baths of silky pH 9.7 water and the rare Murasawa beef — but the big baths are partly recirculated, 2026 guests say the outdoor tubs are gone, and the building shows its age

Nitchoan Keigetsu takes its name from the painter Matsubayashi Keigetsu, who wrote a Chinese poem about the Ina Valley and named the previous head of the house's hermitage 'Nitchōan'. It's a 20-room inn in Hirugami Onsen, a spa town whose water was struck during tunnel work in 1973, and the main draw is that water: an alkaline simple sulphur spring of pH 9.7 that feels slippery on the skin, poured into large baths of kōyamaki (Japanese umbrella pine) and open from check-in until 9:30 the next morning. The inn's own page says the water is not diluted but is partly recirculated for heating. It also claims to be the only inn in Nagano serving Murasawa beef, ordered from Kyoto by cut and weight. Independent blogs are scarce — one onsen blogger stayed in April 2024 — so most recent evidence comes from booking-site reviews. Japanese guests rate it 4.3 across 706 reviews on Jalan (dinner 4.7), 4.23 across 566 on Rakuten Travel and 4.11 across 38 on Ikyu. They praise kind, careful staff (including many staff from overseas), Kyoto-style dashi cooking with local carp, generous breakfasts, the quiet baths and the after-dinner stargazing walk. The 2026 complaints: no outdoor bath (April, August and September 2026), creaking tatami and a weak room shower, rain noise from a leak in a twin room, an uncleaned room tub on arrival, a smell from a room bath, cold dishes, a hard futon and an old building. Standard two-meal plans start at ¥14,300 per person, and reviewers typically paid about ¥17,000–30,000 or more per person.